System and method for visualizing and navigating dynamic content in a graphical user interface

ABSTRACT

A system and method for visualizing and navigating dynamic documents including data from an ongoing process and including instances of specified search terms. A summary view including a condensed abstract representation of a dynamic document provides a global overview of the distribution of search terms. The invention updates the document and aggregates the instances of search terms when the representation includes a nonlinear scale or uses multiple display regions having different resolution levels. The invention supports rapid skimming of dynamic documents and dynamic document collections, including enhancements triggered by cursor brushing, while keeping the user in context. Navigation to a segment of the dynamic document by selecting a corresponding portion of the summary view can replace the use of conventional scrolling techniques.

FIELD OF THE INVENTION

This invention relates to graphical user interfaces and morespecifically to a system and method for visualizing and navigatingdynamic content in a graphical user interface without requiring the useof conventional scrolling techniques.

DESCRIPTION OF RELATED APPLICATIONS

This application is related to two other commonly owned and concurrentlyfiled applications, “System and Method for Visualizing and NavigatingContent in a Graphical User Interface” U.S. patent application Ser. No.10/034,300 and “Navigation Tool for Slide Presentations” U.S. patentapplication Ser. No. 10/034/149, which are incorporated herein byreference.

DESCRIPTION OF RELATED ART

As the volume of data accessible via computer continues to increase, theneed for automated tools for efficient browsing and retrieval ofrelevant information from that data also increases. Many people use theInternet to access a wide variety of documents represented in manydifferent formats, such as plain text, static images, animations,HTML-based web pages, MP3 audio, and video data. Specific information isvery often found by the user through queries to search engines, whichare remotely accessible programs that perform keyword or similaritysearches for information on Internet data.

Unfortunately, it is not always easy for a user to maintain context whennavigating within a large web site or viewing a document. The user mayhave difficulty keeping an overview of a document or collection ofdocuments while focusing on detailed content. This situation isexacerbated when the user is equipped with hardware that has limitedcommunication bandwidth or limited display area and resolution as isoften the case with personal digital assistants (PDAs).

Several different schemes for scanning and selecting items in agraphical user interface are described in “The Alphaslider: A Compactand Rapid Selector” by C. Ahlberg and B. Shneiderman, Proceedings of ACMConference on Human Factors in Computer Systems, Boston, Mass., USA,Apr. 24-28, 1994, pp. 365-371, which is hereby incorporated byreference. This paper recognizes the problem of displaying a largedocument having more points of interest than can be displayed at once ina display, i.e. when there are more items than available pixels. In thissituation, the user needs to select which portions of a document are tobe displayed with navigable resolution. The authors present differentslider mechanisms to help a user select the granularity of theinformation displayed in a slider window. One mechanism features ascroll box slider bar having three different portions, with each portiondesigned to cause either coarse, medium, or fine motion of the sliderbar when grasped by a user. Another mechanism selects granularity basedon mouse movement speed. A third mechanism selects slider motionresolution by having the user move the mouse perpendicularly to thedirection of slider bar movement. The authors report that users wereconfused by such non-intuitive combinations of mouse movement. Userswere also generally frustrated by having to perform fine slider barmovements with the mouse while simultaneously holding down a mousebutton.

An interface having a nonlinear slider scale is described in“TimeSlider: An Interface to Specify Time Point” by Y. Koike et al.,Proceedings of the ACM Symposium on User Interface Software andTechnology, 10^(th) Annual Symposium, UIST '97, 1997, pp. 43-44, whichis hereby incorporated by reference. The TimeSlider interface uses ascale that is nonlinear (i.e. coarsely compressed) at both ends of theslider window, but that has a fine, linear scale in the center portion.This interface thus presents a fisheye view of a document (see also“Generalized Fisheye Views, by George W. Furnas, ACM ConferenceProceedings on Human Factors in Computing Systems, April 1986, BostonMass., pp. 16-23, which is hereby incorporated by reference). The scaledepicts an indicated time span, and is described in the context ofdepicting a history of changes on a desktop. The user must grasp (i.e.select with a mouse button) and hold the slider bar for a specified timeto enable the movement of a desired point on the timeline into thecentral linear region of the scale. A summary window appears when theuser grasps the slider bar, and displays information about the desktopstate or changes thereto. Small marks on the time scale can representtime points at which state changes occurred or points at which there areinteresting items including search keywords.

Another noteworthy interface is described in “A Multi-Scale TimelineSlider for Stream Visualization and Control” by Heather A. Richter etal., Technical Report 99-30 available at the Georgia Tech College ofComputing web site as ftp://ftp.cc.gatech.edu/pub/gvu/tr/1999/99-30.pdf,which is hereby incorporated by reference. This interface is designedfor visualization and playback of long media streams decorated withsignificant events that can help pinpoint an exact location at which tobegin playback of a stream. The article points out the difficulty ofdistinguishing clusters of events when the resolution level is limited,and notes that this difficulty is aggravated when nonlinear time scalesare used. That is, a nonlinear time scale gives the illusion thateverything in the past is significant by clustering all past events intoone visible region in the interface. The interface described in thearticle requires the user to create “focus regions” to zoom in on aparticular document span to try to resolve this clustering problem. Theinterface requires a user to right-mouse-click on a timeline to create anew, subordinate timeline that is a zoomed view of the focus region onthe original timeline. Markers above the timeline depict locations ofspecified events. While the aforementioned prior art tools are usefuladvances in the field of information visualization, GUI tools thatprovide further ease of use could be developed. Such tools would be ofinterest to Internet users who must currently silt and scroll throughlarge collections of potentially immense documents, sometimes withhardware of limited display, storage, and communication capability.Dynamic documents are of particular difficulty as they contain data froman ongoing process and must therefore somehow be updated and displayedwithout causing past points of interest to be clustered togetherindistinguishably. An improved system enabling visualization andnavigation of dynamic documents while keeping the user within context istherefore needed.

SUMMARY OF THE INVENTION

It is accordingly an object of this invention to devise a system andmethod for concise visualization and easy navigation of dynamicdocuments while keeping the user within context. A dynamic documentincludes data from an ongoing process and contains instances ofuser-specified features which may include conventional search terms orkeywords as well as events defined by significant changes in the data. Asearch engine can identify relevant documents and a document analysisand indexing tool can generate related document metadata.

The invention provides a summary view of at least one dynamic documentupon user request. Collections of dynamic documents may also besimilarly summarized. The summary view can be generated from thedocument itself or from the document metadata or both, and can begenerated by a Java applet. The summary view depicts the distributionand frequency of search terms, as an exemplary indication of documentrelevance, within the document using a condensed abstract representationof the document. The invention continuously or periodically updates thesummary view to reflect changes that occur in the document. Dynamicdocuments may include, for example, text files, image files, web pages,audio files, video files, and streaming data. There are many scenariosin which a stream of data is generated by an ongoing process. Emergencyroom equipment or other medical monitoring devices can generate patientdata. A security system can generate an ongoing data stream from anumber of cameras and other sensors. Similarly, theatrical performancesand other such productions can generate data streams to be visualizedand navigated. Computer networks, stock markets, and chat rooms can alsoproduce volumes of dynamic data. The summary view can compute and depicta statistical summary of the contents of a portion of the dynamicdocument selected by a user.

In a preferred embodiment, the summary view comprises a rectangulararrangement of markers in which the columns of the arrangementcorrespond to the user-specified features such as search terms, and therows correspond to different segments of the dynamic document.Alternately, the summary view may be horizontally oriented, so that rowscorrespond to features and the columns correspond to different segmentsof the dynamic document. The content of each marker (for example, thecolor or darkness of each marker) can represent the presence or absenceof search terms, or the frequency with which search terms occur in theportion of the document represented by that particular marker, or otheruseful relevance measures. Similarly, the physical dimensions of thesummary view may encode metadata values for the dynamic document.

The dynamic document is preferably represented in the condensed abstractrepresentation by several distinct segments, each of which may have itsown different resolution scale. A substantially nonlinear abstractrepresentation of the document is depicted by using many differentlevels of resolution for corresponding segments of a dynamic document.Each segment may for example represent a span of time over which theongoing process generated data to be viewed and navigated. Alternately,segments may be defined by properties of the data in the stream (forexample, significant changes in a measured value). A segment depictingrecent events may use a higher resolution scale than a segment depictingold events, as old events are often less significant than recent events.The summary view is preferably vertically oriented to more intuitivelycorrespond with a stream of data, with the most recent data depicted atthe bottom of the summary view and the data moving upward over time.Alternately, the summary view can be horizontally oriented to resemble astrip chart with data flowing from left to right over time. The summaryview thus provides an immediate overview of the document as well as thedistribution of interesting features throughout the document as anexemplary indication of document relevance.

It is a related object of the invention to more readily distinguishclusters of feature instances in a dynamic document. As data continuesto stream in, and feature instances are moved into document segmentshaving lower display resolution, the number of pixels available persearch term instance declines. The invention avoids the distortion ofdepicted data in this situation by aggregating information in thesummary view. The summary view can be included within a modified versionof a dynamic document, or may be embodied as a fold-out window thatappears to float above a displayed document.

It is a related object that different features such as search terms orterm categories be depicted with different colors in the summary viewwhen feasible to help the user maintain the context of the informationvisualization and navigation experience. A legend of the search terms orterm categories in the different colors may help prevent user confusion.

It is a related object that the summary view utilizes cursor “brushing”,the juxtaposition of a cursor near or over a marker, to trigger anenhancement of the summary view providing more detailed information. Forexample, a contextual snippet of information including a particularsearch term and several surrounding words from the particular portion ofa document represented by a marker can be displayed when a user movesthe cursor over that marker.

It is a related object that such visualization and navigation not relyon the use of conventional scrolling techniques as practiced withconventional web browsing programs, although the invention can be usedwith web browsers. Users may use the summary view to determine thecontext in which search terms occur in a document, and in responsechoose to directly navigate to a particular occurrence of a search termin the document. When the user clicks on a particular marker, theinvention responsively scrolls the document so that the portion of thedocument corresponding to the marker is displayed, and data accessbegins from that point.

It is a related object that a hierarchy of summary views may begenerated by the invention. Each summary view in the hierarchy depictsincreasingly detailed summary information about portions of the documentuntil finally a particular portion of the document is directlydisplayed.

It is a related object that the invention serves as an intermediary thatenables intuitive visualization and navigation capabilities withoutcausing distraction or confusion to users who are accustomed toconventional web browser use. It is a related object that the improvedvisualization and navigation means may be of particular utility to usersof computer systems having limited storage, display, and communicationcapability. This is often the case with PDAs, personal informationmanagers (PIMs) and cellular phones or other platforms incorporatingmicrobrowsers.

It is a related object that the visualization and navigation systemprovide summary information about various features of documents that arelinked to a document currently being displayed, without requiring thatlinked documents be pre-fetched in their entirety. This summaryinformation may include thumbnails of other documents linked to thedocument currently being displayed, or indications of the presence anddistribution of search terms in linked documents. The user may thereforechoose whether to click on (and thus navigate to) a linked documentbased on the summary information. The summary information may alsoinclude a description of the number of accesses that have been made tothe linked documents or portions thereof. For example, the darkness ofdepicted cells may correspond to the popularity of a document portion.

It is a related object that the invention enable improved visualizationand navigation of video files. For example, each row in a summary viewcan correspond to a section of the video data selected by a segmentationtool. When a user brushes a cursor over a marker, the invention displaysa video frame corresponding to the segment of video data represented bythe marker. When the user clicks on a marker or video frame, theinvention scrolls to the corresponding segment in the video data andbegins playing the video in the display at the beginning of the selectedsegment. For video collections, a first hierarchical fold-out window mayrepresent a plurality of videos, with subsequent fold-out windows in thehierarchy representing individual videos, and then segments ofindividual videos and so forth to a point where the video itself beginsplaying in the display. Alternately, the invention may display astoryboard comprising a plurality of video frames, possibly arranged ina serpentine fashion, with navigation enabled as described above. Theforegoing objects are believed to be satisfied by the embodiment of thepresent invention as described below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of the summary view of the preferred embodiment ofthe present invention.

FIG. 2 is a diagram of the summary view of the preferred embodiment ofthe present invention in a security system scenario.

FIG. 3 is a diagram of the summary view of the preferred embodiment ofthe present invention in a theatrical performance scenario.

FIG. 4 is a diagram of the summary view of the preferred embodiment ofthe present invention including a statistical summary of a selecteddocument portion.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The typical invention use scenario begins with the user starting a webbrowser providing a graphical user interface, and then specifyingfeatures such as keywords or other search terms that are of interest.The graphical user interface may for example be generated by a digitalcomputer, a personal digital assistant, a personal information manager,or a microbrowser application running on a cellular telephone. A searchengine can provide links to documents that it discovers and deemsrelevant based on an analysis of the instances of search terms found insuch documents. Search engines are generally known in the art and arereadily familiar to persons looking for information in digital datastored in networks like the Internet. Of course, a user may select adocument directly. Non-browser-based scenarios are also supported by theinvention.

Documents may include text files, image files, web pages, audio files,and video files for example, as well as collections. A multimediaanalysis and indexing tool, such as IBM's CueVideo toolkit, may generatedocument metadata, particularly for multimedia documents. For example,document metadata may include search terms, a textual transcript, theresults of a textual transcript search, the results of a speaker changesearch, the results of a stress analysis, topic headings, the results ofa topic change search, the results of a speech transcript search, audiofeatures, the audio amplitude data, and the number of accesses to aparticular document segment.

Documents are not necessarily static items. Dynamic documents includedata from an ongoing process and therefore change with time. The featursof interest may thus include user-specified events that are defined bysignificant changes in the data. Many data sources generate informationon an ongoing basis that needs to be monitored for both current valuesand for emerging trends. Streaming data, an example of a kind of dynamicdocument, is becoming increasingly popular among Internet users as largemultimedia documents are made available for distribution. Furtherexamples of dynamic documents are given below. For such data sources, itis often necessary to show the user recent history and to enable theuser to get detailed information about events occurring at a certainpoint in time. A historic overview is often necessary to provide thecontext to understand the current state. Time-varying data frequentlyshows characteristic recurring patterns and trends that are easy to missif only the current data state is visible.

Referring now to FIG. 1, a diagram of the summary view of the preferredembodiment of the present invention is shown. Summary view 100 isessentially a condensed abstract representation of at least one of thedynamic documents a user wishes to visualize and navigate. A Java appletcan generate summary view 100 from the document itself, or from thedocument metadata, or both. Summary view 100 depicts the structure ofthe document, as well as the distribution and frequency of search termswithin the document's various segments (which may be defined by anindexing tool or merely represent a straightforward segmentation of thedocument). The distribution and frequency information define a searchterm density distribution that a user would find useful when decidingwhether to view and navigate a particular document's content. Summaryview 100 can also depict other useful relevance measures.

Summary view 100 comprises rows 102, columns 104, and markers 106 in arectangular arrangement. In this embodiment, rows 102 correspond tosegments of the document and columns 104 correspond to theuser-specified search terms 108. Alternately, rows 102 can correspond tothe user-specified search terms 108 and columns 104 can correspond tosegments of the document. Search terms 108 are displayed to help remindthe user of column 104 meanings, helping to keep the user oriented andwithin the context of the information retrieval effort. Scale indicia110 describe the range of data depicted by summary view 110. Eachsegment of summary view 110 can represent for example a span of timeover which the ongoing process generated data to be viewed andnavigated. As shown in FIG. 1, scale indicia 110 describe the timeduration from the present to the arrival time of data depicted bymarkers 106 at various row 102 and column 104 locations. The lowest row102 in FIG. 1 depicts the most recent data (e.g. “now”), and upper rows102 depict increasingly older data (e.g. “15 minutes”, “1 hour” etc.).Summary view 100 is preferably vertically oriented to more intuitivelycorrespond with a stream of data as would be generated by a printer orteletype, with the most recent data depicted at the bottom of summaryview 100 and older data moving upward over time. Alternately, summaryview 100 can be horizontally oriented to resemble a strip chart withdata flowing from left to right over time.

Summary view 100 preferably depicts a dynamic document as distinctsegments in distinct representation regions, with each region having itsown resolution scale. For example, in FIG. 1 the lowest region depictsdata from “now” to “15 minutes” ago at a scale of approximately tenminutes per inch, while the next region up depicts data from “15minutes” ago to “1 hour” ago at a scale of approximately 40 minutes perinch. Subsequent regions depict older data at even lower resolution,because older data tends to be less significant than recent data andthus deserves less area in the graphical user interface. A substantiallynonlinear abstract representation of the document is therefore depictedby using many regions each having different levels of resolution forcorresponding segments of a dynamic document. The invention updatessummary view 100 to reflect changes that occur in the document. Theinvention may continuously update incoming dynamic document data andanalyze the data for features of interest, which are then displayed insummary view 100. Alternately, the invention may update the dynamicdocument periodically, and then update its abstract representation insummary view 100.

In this instance, the search terms 108 describe how a radio listenerspent a portion of listening time, e.g. either scanning through a listof streaming online radio stations (“SCAN”) or listening to a particularone of three stations (“WREK”, “WXXX” and “WYYY”). Here, rows 102 in thelowest segment each represent one minute of time, and the darkness ofeach marker 106 specifies how much of that minute was spent listening toa particular station.

More generally, the content of each marker 106 represents the frequencywith which a particular search term 108 occurs in the portion of thedocument represented by that particular marker 106 positioned at aspecific combination of row 102 and column 104. The relative darkness ofeach marker 106, or color according to a color legend, depicts thedensity of each search term 108. Alternately, different marker 106patterns (e.g. dots, cross-hatching) may be assigned to representdifferent densities. Each search term 108 and markers 106 correspondingto that search term 108 can be displayed in a different color than othersearch terms 108 and their corresponding markers 108. Color coding canhelp the user maintain the context of the information visualization andnavigation experience, and prevent user confusion. The physicaldimensions of summary view 100 and its separate components may alsoencode metadata values; for example, search terms 108 not occurringfrequently anywhere in the document may be represented by thincorresponding columns 104. Summary view 100 can be included within amodified version of a dynamic document, or may be embodied as a fold-outwindow that appears to float above a displayed document.

Summary view 100 thus provides an immediate overview of the document aswell as the distribution of interesting features throughout the documentas an exemplary indication of document relevance. The invention isdesigned to serve as an intermediary that enables intuitivevisualization and navigation capabilities without causing distraction orconfusion to users who are accustomed to conventional web browser use.Users of the invention can easily monitor the recent history of amonitored process and quickly navigate to a particular location ofinterest for more detail, to be described below.

The use of low resolution regions in summary view 100 can cause problemswhen there are more search terms 108 occurring than there are pixelsavailable to assign so that each marker 106 gets at least one pixel. Inother words, as data continues to stream in, and search term 108instances are moved into document segments having lower displayresolution, the number of pixels available per search term 108 instancedeclines. Clusters of search term 108 instances need to bedistinguishable by a user as dynamic data moves between regions ofdifferent resolution.

The present invention avoids the confusion that could result fromdistortion of depicted data by aggregating information in summary view100 as data is updated. As the data moves upward in summary view 100, itgets aggregated into a lower-resolution representation. Thus, searchterm 108 instances that are initially each depicted by their own markers106 as point features are converted into aggregating features by thepresent invention. The representation of aggregating features is similarto that of point features, but the data displayed by markers 106 foraggregating features is cumulative for the span represented by aparticular row 102.

For example, in FIG. 1, the first fifteen minutes of data are depictedwith markers 106 having a one minute resolution, while the segmentdepicting data from 15 minutes to one hour in age uses markers 106 offive minute resolution. As data moves into the section with five minuteresolution, five of the one-minute markers 106 get aggregated into asingle five-minute marker. In other words, data represented by each ofthe five one-minute markers is summed and then appropriately representedby the single five-minute marker. Similarly, as data moves above the “1hour” demarcation line, each marker 106 would depict the number ofsearch term 108 instances occurring within say a fifteen minute span.This method of aggregation can keep markers 106 all the same size, whichhelps users interact with them more easily. Alternately, each marker 106can depict a search term 108 frequency by normalizing each valuedepicted by a marker 106 to the span allocated to the particular row 102in which marker 106 appears, e.g. data is converted to “events perpixel” and depicted accordingly.

Through aggregation, the present invention thus depicts not only directdata, such as the instances of search term 108 occurrences themselves,but metadata derived from direct data. If more than one level ofaggregation is depicted, as when data moves above the “1 hour”demarcation line in this example, it may be adequate for the depictedmetadata to be derived from first level aggregation metadata, versuskeeping a large file of direct data available at all times. In otherwords, a summary of the direct data may itself be summarized as itscrolls into history.

Referring now to FIG. 2, a diagram of the-summary view of the preferredembodiment of the present invention is shown in a security systemscenario. As in the previous Figure, summary view 200 includes rows 202,columns 204, markers 206, search terms 208, and scale indicia 210 whichin this case depict specific times (e.g. “now”, “8 am”, etc.). Searchterms 208 here are the openings of various doors (e.g. “Door A”, “DoorB”, etc.) as detected and reported by security sensors, and displayed bymarkers 206. When reviewing the security data, it is easy to discernwhether a door was opened recently by the presence or absence of amarker 206. Detection of a deviation from a predictable event pattern isvery easy with the present invention. The hourly tour of a guard throughthe building causes a regular pattern of door openings in the securitydata stream, so any missed checkpoint would be very distinctive.

Security systems also often use many surveillance cameras that need tobe monitored. It is well known that even after short monitoring times,people easily miss events seen by the cameras. With the presentinvention, a user could easily detect changes in historical video dataand responsively go back into the data stream for further investigation.For example, if two door openings are recorded in the data stream, auser could quickly check the video data to see if an intruder entered orif a guard merely backtracked momentarily to re-check a door.

The user triggers the creation of an enhancement 212 in the presentinvention by moving a cursor (not shown) in the graphical user interfacenear or over a particular marker 206. Enhancement 212 is an addition tosummary view 200 providing more detailed information. The juxtapositionof a cursor near or on a graphical user interface target is termed“brushing” and is distinct from selection of that target by clicking amouse button. Brushing requires less commitment from the user thantarget selection, and causes less confusion because brushing results aretemporary and are usually ‘undone’ when the user moves the cursor awayagain. In this example, enhancement 212 includes a fold-out window thatincludes video frames or clips taken from several different cameras overa time span represented by a particular row 202 containing the brushedmarker 206. Guide lines help the user stay in context by unobtrusivelyidentifying the particular row 202 to which enhancement 212 corresponds.Highlighting of a marker 206 boundary in response to cursor proximityaccomplishes a similar effect. In other examples, enhancement 212 maycomprise a display of the first few words from a particularcorresponding document segment, or a contextual snippet having a searchterm and a number of surrounding words to help the user determine howsearch term 208 relates to nearby document content.

If the user decides that the instance of search term 208 is likely to beof interest, then the user can navigate directly to that instance in thedocument by selecting the corresponding particular marker 206. Forexample, when the user clicks a mouse button to select a particularmarker 206, the invention scrolls the document so that the portion ofthe document corresponding to that particular marker 206 is directlydisplayed. The present invention therefore does not rely on the use ofconventional scrolling techniques as practiced with conventional webbrowsing programs for document navigation, although the invention islikely to be used with web browsers.

As described in detail in cross-referenced and incorporated-by-referencepatent application “System and Method for Visualizing and NavigatingContent in a Graphical User Interface”, a hierarchy of summary views maybe used to represent a very large amount of data. This is true for thedynamic documents described in this patent application as well as forthe “fixed” documents described in that application. For example,summary view 200 depicts about eight hours of dynamic data from asecurity system. If a month of dynamic data needed to be visualized andnavigated with similar precision, a single summary view 200 wouldprobably not suffice. In that situation, the first summary view 200 in ahierarchy would for example depict the entire month, and a secondsummary view in a hierarchy of summary views generated in response touser commands would for example depict a particular day's data. In thismanner, each subsequent representation in a hierarchy of representationsdepicts information at an increased resolution. Old data can beperiodically archived into a “fixed” document.

Any task involving the monitoring of streaming data can benefit from useof the present invention, as it provides the user with a high leveloverview of the data and allows the user to access detailed data from aselected point in time. One application is to monitor patients in ahospital emergency room or intensive care unit. The dynamic documentincludes medical data about the patient like heart rate, blood pressure,respiration rate, temperature, the times and dosages of medicationsgiven, and other physician-defined parameters, and possibly images froma surveillance camera in the patient's room. If the summary view shows asudden surge in heart rate, for example, it is a simple matter to checkand see that the patient moved around or had a visitor at that point intime. Similarly, if a slow but steady change in some parameter occursover time and thus might normally go unobserved, the change may bedetected at a glance using the nonlinear time scale of the presentinvention. Unlike plotters that continuously trace parameters on longstrips of paper, such as a cardiogram for example, the present inventioncollects all relevant data at one point (with current events and historyin close proximity) and enables quick visualization and navigation toinvestigate what happened at a specific point in time. Anotherapplication is an awareness system for a work group, in which columns204 represent group members and the features depict the status of agroup member at a given time (in, out, at lunch, in a meeting, and soforth).

Referring now to FIG. 3, a diagram of the summary view of the preferredembodiment of the present invention in a theatrical performance scenariois shown. As in FIG. 2, summary view 300 includes rows 302, columns 304,markers 306, search terms 308, scale indicia 310, and an enhancement312. In this case, scale indicia 310 describe acts and scenes, andsearch terms 308 describe the onstage presence or absence of differentcharacters throughout the performance. Enhancement 312 is a fold-outwindow including video data from a number of cameras positionedthroughout the theater, preferably oriented to present a coherentoverall performance depiction to the user. Enhancement 312 can alsoinclude a text transcript of the performance, background materials,links for annotations, and other educational material. The dynamicdocument may thus include not only data from the performance but inputfrom the audience.

Referring now to FIG. 4, a diagram of the summary view of the preferredembodiment of the present invention including a statistical summary of aselected document portion is shown. As in several previous Figures,summary view 400 includes rows 402, columns 404, markers 406, searchterms 408, scale indicia 410 and an enhancement 412. This Figure relatesto another application of the invention, which is to monitor web logfiles. Web servers continuously generate a huge amount of data that istypically analyzed only once a month or less. Trends in server usagewill therefore be detected very late, and irregularities in serveraccess, including denial of service attacks, might be detected too late.The present invention allows a user to see severe changes in the overallserver access patterns by monitoring, for example, the number of pagesaccessed, the number of accesses to specific directories, the number ofpage updates, and the number of type 404 errors (attempted accesses tonon-existing pages). A surge in type 404 errors might indicate a hackerattack. Span selectors 414 and 416 define a data range for which astatistical summary is computed by the invention and displayed inenhancement 412. Such a summary can be compared to a “baseline” summaryto help detect anomalies in the dynamic document data. Similarcomparisons can be made on stock market data.

The present invention can also depict activities in a textual chat room.Each participant is assigned to a column, so it becomes very easy tofind all messages from a particular person. Private messages betweenonly two people in the chat room could be shown in a different color.The span selection described above can be used to select a time rangefor which a transcript of the chat is to be written to a file.Similarly, the messages of some participants can be eliminated from thelog by checking off corresponding columns prior to writing the file.Additional columns can indicate non-conversational messages, such aswhen people entered or left the chat room.

A general purpose computer is programmed according to the inventivesteps herein. The invention can also be embodied as an article ofmanufacture—a machine component—that is used by a digital processingapparatus to execute the present logic. This invention is realized in acritical machine component that causes a digital processing apparatus toperform the inventive method steps herein. The invention may be embodiedby a computer program that is executed by a processor within a computeras a series of computer-executable instructions. These instructions mayreside, for example, in RAM of a computer or on a hard drive or opticaldrive of the computer, or the instructions may be stored on a DASDarray, magnetic tape, electronic read-only memory, or other appropriatedata storage device.

While the invention has been described with respect to an illustrativeembodiment thereof, it will be understood that various changes may bemade in the apparatus and means herein described without departing fromthe scope and teaching of the invention. Accordingly, the describedembodiment is to be considered merely exemplary and the invention is notto be limited except as specified in the attached claims.

1. A method for visualizing dynamic documents in a graphical userinterface of a web browser, comprising: generating a summary view thatdepicts structure of a dynamic document from a data stream, the summaryview including distribution and frequency of search terms, withinsegments of the dynamic document to indicate relevance of the dynamicdocument based on said search terms, the distribution and frequency ofsaid search terms are represented using a condensed abstractrepresentation of a search term density distribution, wherein: saidcondensed abstract representation comprises a marker selected from thegroup consisting of: color, pattern, and relative darkness, and saidsummary view comprises a plurality of rows, columns, and markers in arectangular arrangement, each of said markers comprises content thatrepresents frequency with which one of said search terms occur in aposition of the dynamic document; updating said summary view to reflectchanges that occur in said dynamic document from said data stream; andtriggering an enhancement of said summary view by cursor brushing aparticular marker, said enhancement providing additional information ofthe structure of the dynamic document.
 2. The method of claim 1 furthercomprising navigating to at least one segment of said dynamic documentby selecting a corresponding portion of said summary view.
 3. The methodof claim 1 further comprising computing a statistical summary ofcontents of a portion of a selected dynamic document.
 4. The method ofclaim 1 further comprising identifying dynamic documents that arerelevant to said search terms using at least one search engine.
 5. Themethod of claim 1 further comprising aggregating information to enable amore condensed abstract representation of said dynamic document.
 6. Themethod of claim 1 wherein said updating is performed periodically. 7.The method of claim 1 wherein said updating is performed continuously.8. The method of claim 1, wherein at least one segment of said dynamicdocument is navigated to by selection of a corresponding portion of saidsummary view.
 9. The method of claim 1, wherein said search termsinclude user-specified events defined by significant changes in saiddistribution and frequency from said data stream.
 10. The method ofclaim 1, wherein said summary view comprises a number of distinctregions, each region having a different resolution scale, enablinginformation to be depicted at different levels of detail.
 11. The methodof claim 10, wherein said resolution scale is a time scale.
 12. Themethod of claim 1, wherein said abstract representation is nonlinear.13. The method of claim 1, wherein said summary view depicts more recentevents with higher resolution than less recent events.
 14. A computerprogram product for visualizing dynamic documents in a graphical userinterface of a web browser, the computer program product comprising acomputer readable storage medium having computer-executable programinstructions embodied therewith: first code instructions for generatinga summary view that depicts structure of a dynamic document from a datastream, the summary view including distribution and frequency of searchterms within segments of the dynamic document to indicate relevance ofthe dynamic document based on said search terms, the distribution andfrequency of said search terms are represented using a condensedabstract representation of a search term density distribution, wherein:said condensed abstract representation comprises a marker selected fromthe group consisting of: color, pattern, and relative darkness, and saidsummary view comprises a plurality of rows, columns, and markers in arectangular arrangement, each of said markers comprises content thatrepresents frequency with which one of said search terms occur in aposition of the dynamic document; second code instructions for updatingsaid summary view to reflect changes that occur in said dynamic documentfrom said data stream; and third code instructions for triggering anenhancement of said summary view by cursor brushing a particular marker,said enhancement providing additional information of the structure ofthe dynamic document.
 15. The computer program product of claim 14,further comprising: fourth code instructions for navigating to at leastone segment of said dynamic document by selecting a correspondingportion of said summary view.
 16. The computer program product of claim14, further comprising: fourth code instructions for computing astatistical summary of contents of a portion of a selected dynamicdocument.
 17. The computer program product of claim 14, furthercomprising: fourth code instructions for identifying dynamic documentsthat are relevant to said search terms using at least one search engine.18. The computer program product of claim 14, further comprising: fourthcode instructions for aggregating information to enable a more condensedabstract representation of said dynamic document.
 19. The computerprogram product of claim 14, wherein said updating is performedperiodically.
 20. The computer program product of claim 14, wherein saidupdating is performed continuously.
 21. The computer program product ofclaim 14, wherein at least one segment of said dynamic document isnavigated to by selection of a corresponding portion of said summaryview.
 22. The computer program product of claim 14, wherein said searchterms include user-specified events defined by significant changes insaid distribution and frequency from said data stream.
 23. The computerprogram product of claim 14, wherein said summary view comprises anumber of distinct regions, each region having a different resolutionscale, enabling information to be depicted at different levels ofdetail.
 24. The computer program product of claim 23, wherein saidresolution scale is a time scale.
 25. The computer program product ofclaim 14, wherein said abstract representation is nonlinear.
 26. Thecomputer program product of claim 14, wherein said summary view depictsmore recent events with higher resolution than less recent events.